Difference between revisions of "Template:cpp/container/erase2"
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#include <cassert> | #include <cassert> | ||
#include <inplace_vector> | #include <inplace_vector> | ||
Revision as of 13:43, 28 August 2024
| Defined in header <inplace_vector>
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| template< class T, std::size_t N, class U /* = T <- should be!, see e.g. P2248 */ > constexpr typename std::inplace_vector<T, N>::size_type /* <- down with typename! */ |
(1) | (since C++26) |
| template< class T, std::size_t N, class Pred > constexpr typename std::inplace_vector<T, N>::size_type /* <- down with typename! */ |
(2) | (since C++26) |
1) Erases all elements that compare equal to value from the container. Equivalent to
auto it = std::remove(c.begin(), c.end(), value); auto r = std::distance(it, c.end()); c.erase(it, c.end()); return r;
2) Erases all elements that satisfy the predicate pred from the container. Equivalent to
auto it = std::remove_if(c.begin(), c.end(), pred); auto r = std::distance(it, c.end()); c.erase(it, c.end()); return r;
Contents |
Parameters
| c | - | container from which to erase |
| value | - | value to be removed |
| pred | - | unary predicate which returns true if the element should be erased. The expression pred(v) must be convertible to bool for every argument |
Return value
The number of erased elements.
Complexity
Linear.
Example
Run this code
#include <cassert> #include <inplace_vector> #include <numeric> int main() { std::inplace_vector<int, 10> v(10, 0); std::ranges::iota(v, 0); std::println("Initially, v = {}", v); auto erased = std::erase(v, 3); std::println("After erase(v, 3), v = {}", v); assert(erased == 1); erased = std::erase_if(v, [](int x) { return x % 2 == 0; }); std::println("After erasing all even numbers, v = {}", v); std::println("Erased even numbers: {}", erased); }
Output:
Initially, v = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] After erase(v, 3), v = [0, 1, 2, 4, 5, 6, 7, 8, 9] After erasing all even numbers, v = [1, 5, 7, 9] Erased even numbers: 5
See also
| removes elements satisfying specific criteria (function template) | |
| (C++20)(C++20) |
removes elements satisfying specific criteria (niebloid) |
